Fabric tester



y 4, 1957 K. E. FRYFOGLE ETAL 3,329,010

. FABRIC TESTER Filed March 12, 1965 2 Sheets$heet l INVENTORS. CLINTON d.T. YOUNG & KENNETH E. FRYFOGLE ATTORNEY July 4, 1967 Filed March 12, 1965 INDICATING HAND K. E. FRYFOGLE ETAL FABRIC TESTER 2Sheets-Sheet 2 RETRA CT\ ACTUATING CYLINDER (IN HAND UNIT) STRETCH BATTERY ASSEMBLY MOTOR 6o INVENTORS.

CLINTON ail. You e By & KENNETH E. FRYFOGLE S2 T AUTOMATI c L! M \T ATTORNEY United States Patent 3,329,010 FABRIC TESTER Kenneth E. Fryfogle, Greenville, S.C., and Clinton J. T. Young, Alexandria, Va., assignors to Mount Vernon Mills, Inc., Baltimore, Md., a corporation of Maryland Filed Mar. 12, 1965, Ser. No. 439,345 4 Claims. (Cl. 73-97) This invention relates to a device for testing the tensile strength of fabrics and the like.

The invention has particular application to the testing of dryer-felts, although many other fabrics and the like may be tested through the use hereof.

Dryer-felts used by the paper industry are extremely wide, heavy endless fabric belts from about 70 to 341 inches in width and in lengths from to 150 yards. Dryer-felts are relatively expensive, and it is desirable to run them as long as possible. When the dryer-felt breaks because of weakening due to age and use considerable damage may be caused to personnel, as well as the paper making machinery. It is normal practice to schedule the changing of dryer-felts so that such changes may occur at a time when the machine is not scheduled for production and requires other maintenance work. The breaking of the dryer-felt requires that the machine be put out of production for some considerable period of time while a new felt is installed thus, occasioning considerable machine downtime and further expense. Fabric testers are available for conducting what is known as Grab Tests but such requires the placing of samples of the fabric between gripping jaws. These jaws are carried by a machine which is not portable and must be relatively large in order to effect proper gripping upon the fabric. It is not desirable to cut samples from the larger fabric to be tested because in the case of dryerfelts such would no longer be usable. Rather extensive samples are often desirable as in the case of dryer-felts where testing is to be conducted both in the direction of the warp and in the direction of the filling. When spills of various chemicals occur on dryer-felts it is often de sirable to test a particular area in which the spilling occurs. Such may occur between the selvages of the dryerfelts which would be entirely inaccessible to tests such as are currently used other than by cutting out a section in the middle of the dryer-felt. It is desirable therefore, to have a tester which may be carried manually for testing any portion of a fabric and which will not damage the fabric so as to leave same in condition for further use.

Accordingly, it is an important object of this invention to provide a portable fabric tester.

Another important object of this invention is to provide a fabric tester for dryer-felts which may be applied to any portion of the dryer-felt while the dryer-felt is still upon the machine without damage to the dryer-felt.

Another object of the invention is to provide-a fabric tester of simple inexpensive construction capable of exerting an effective gripping force thereon without damage to the fabric.

The construction designed to carry out the invention Will be herein described, together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown and wherein:

FIGURE 1 is a side elevation illustrating a fabric tester constructed in accordance with the present invention,

FIGURE 2 is a plan view further illustrating the fabric tester of FIGURE 1,

FIGURE 3 is a schematic diagram of a hydraulic circuit for use in the embodiment of the present invention illustrated,

FIGURE 4 is a schematic plan view of an indicator useful in the embodiment of the present invention illustrated,

FIGURE 5 is a transverse sectional elevation taken through the central portion of and looking from the bottom of FIGURE 4 with the indicating hand advanced to contact the depending finger of the other hand, and

FIGURE 6 is a schematic electrical diagram illustrating the circuit of the present embodiment of the invention hereof.

Referring more particularly to the drawings, a device for testing the tensile strength of fabric and the like, especially but not limited to dryer-felts F, is illustrated. The device includes a pair of aligned supports A and B, respectively. Mounting means C is provided for carrying said supports for movement toward and away from each other. A plurality of spaced aligned sharp prong-like elements D carried by the base of each of said supports serve to grip the fabric. The prong-like elements D, carried by respective supports A and B, extend outwardly thereof away from the supports at an angle with respect to respective supports such that a portion of the prong-like elements overlie respective supports A and B. Such angle is sufficient for the prong-like elements D to pass through and accommodate the fabric between the portion of said prong-like elements overlying said supports and the support effecting a grip on the fabric resisting tension in the fabric between prong-like elements carried by respective supports produced by movement of the supports away from each other. Power operated means E applying measured controlled force moving the supports A and B away from each other against the tension of the fabric is operatively connected to the supports.

FIGURE 1 illustrates the spaced prongs D carried by the supports A and B passing through a multiply fabric in the form of dryer-felt F, mounted upon paper making machinery. It will be noted that the dryer-felt is so impaled upon the prongs D that when the supports A and B are moved apart through the application of force by thte power operated means B an increasing tension will be applied in the fabric as the supports or blocks A and B are moved further and further apart. The supports A and B are each essentially rectangular blocks having fiat lower surfaces 10. Each block has a recess, as illustrated at 11 in the block A, and spaced holes 12 are provided for accommodating the prongs D. The prongs D are pressed into the holes 12, and the recesses 11 are filled with suitable medium for retaining the prongs, such as a suitable epoxy resin 13.

The mounting means C for carrying the supports A and B includes housings 14 and 15, respectively, as well as a pair of longitudinal parallel horizontally spaced mounting bars 16 and 17. The mounting bar 16 is illustrated as being fixed adjacent one end thereof to the housing 14 as by the setscrew 18 which extends into the bar. The bar 17 is similarly secured to the housing 14 as by a setscrew (not shown). The housing 14 includes an enlarged longitudinal medial portion 14a for accommodating a portion of the power operated means E as will be described in greater detail below. The housing 15 includes a longitudinal medial cylindrical portion 15a comprised within the cylinder portion of the power operated means E. A standard 15!) is carried upon the cylindrical portion 15a for supporting the horizontal handle 19. A suitable housing portion 15c also forms a part of the housing 15. It will be noted that the housing 15 slidably accommodates each of the bars 16 and 17 through longitudinal bores (one of which is illustrated at 16a in FIGURE 2).

3 The horizontal handle 19 is attached to the standard 15b as by the screw 20.

It will be especially noted that the prong-like means D carried by the support A extend outwardly from the lower fiat surface 10, and are inclined away from the support B. The prong-like members D carried by the support B incline outwardly away from the support A so that fabric F, illustrated in the form of a dryer-felt in FIGURE 1, may be impaled thereon, and tighten their grip as the supports are moved apart. The prong-like elements D are sharpened at their ends as at 21 and overlie respective lower surface portions of the supports A and B. The power operated means E applies measured controlled force tending to move the supports A and B away from each other against tension imparted to the fabric through the prong-like elements D.

The power operated means E includes a cylinder having a cylindrical bore 22 formed within the cylindrical portion 150 of the housing 15. A piston 23 is carried within the cylinder 22, and a piston rod 24 is fixed thereto. The piston rod 24 is fixed adjacent its end remote from the piston to the housing 14 by the pin 25. The open end of the cylindrical bore 22 is closed by a suitable cap 26, which is threadably carried by the threads 27 upon the cylindrical housing portion 15a. The cap 26 has a suitable hydraulic connection 28 for comunication with the bore 22. A similar hydraulic connection 29 communicates through the mounting 15d with the cylindrical bore 22 on the other side of the piston adjacent the closed end thereof.

The hydraulic system of the power operated means E is illustrated in FIGURE 3. Pressure is generated by the pump which is driven by the motor. A check valve 30 ahead of the pump prevents backward flow during a recovery stroke of the pump while a check valve 31 prevents flow into the reservoir during a pressure stroke. A four-way valve 32 in the stretch position, when the motor is running, permits the pump to move oil from the res ervoir to the hydraulic connection 28 through the flexible line 33, and permits oil from the other side of the piston 23 to flow through the hydraulic connection 29 into the flexible line 34 and from thence to the reservoir. Thus, the supports A and B are forcefully moved apart and as they are moved further and further apart increasing tension will be applied to the fabric F. With the valve in the retract position illustrated in dotted lines in FIGURE 3 oil from the pump enters the cylinder 22 from the line 34 through the connection 29 so that the blocks or supports A and B are forcefully moved towards each other and oil from the other side of the cylinder returns to the reservoir through the line 33. Pressure applied to the piston 23 is measured by a hydraulic gauge described below.

The construction of the gauge is illustrated schematically in FIGURES 4 and 5. The gauge has an indicating hand 35 adapted to move responsive to hydraulic pressure at all times in any desired manner. A lazy hand 36 is moved when the indicating hand enegages a depending finger 36a carried by the lazy hand 36. The lazy hand 36 is pivoted in the cover 37 as at 38. This pivotal connection supplies suflicient friction to maintain the lazy hand in a position to which it is moved, but insufficient to appreciably impede movement of the lazy hand responsive to movement of the indicating hand 35. A knob 39 projects above the cover 37 for setting the lazy hand at a desired position. An electrical connection is provided to close an electrical circuit when the indicating hand 35 touches the depending finger 36a. Such electrical connection includes a strip of metal, preferably a light leaf spring 40, which is fixed to the dial 41 through screws 41a, but which is electrically insulated from the dial. Electrical contact, however, is made by the leaf spring 40 with the pivot 38 of the lazy hand. Another contact 42 is added for making contact with the indicating hand when it reaches its extreme indicating position. Such contact 42 is provided to prevent damage because, when the pin blocks A andB have reached their ultimate position in a direction either toward or away from each other, pressure tends to rise rapidly in the system. It will be noted that indicia 43 are provided on the dial and that a zero pin 44 is carried by the dial.

The electrical system of the power operated means is illustrated schematically in FIGURE 6. The switch S1 is positioned in the hand unit which comprises that portion of the device illustrated in FIGURES 1 and 2. When the switch S1 is closed the motor is connected to the battery 45 and the hydraulic system functions as described above unless the relay RL1 is actuated. When the switch S2, which is called the Automatic Limit switch, is in the on position a path from the battery to ground and back to the battery through the relay will be established whenever the indicating hand 35 touches the depending finger 36a of the lazy hand 36. Such actuation of the switch RL1 opens the circuit to the motor. It is thus possible to set lazy hand 36 at a desired test limit and have increased of load stop at this point if the fabric remains unbroken. Contact between the indicating hand and the lazy hand is momentary and leakage of hydraulic fluid will cause the indicating hand to move backward when the motor stops and this could result in a chattering action or series of momentary stops if the switch S1 were left closed. To prevent this a second pair of contacts 46 in relay RL1 provide a holding current so long as S1 remains closed. Another function of RL1 is to set a limit on hydraulic pressure developed in the system. If the switch S1 were left closed, and the supports A and B moved as far as possible, either from reaching the end of travel of the actuating cylinder 22 or from being engaged in a strong dryer-felt, the motor would still work to increase the pressure. Therefore, when the indicating hand 35 reaches the highest desired functioning position it touches the terminal contact 42. This allows current to flow through the relay RL1 to stop the motor and this action takes place whether the switch S2 is open or closed.

The battery 45 may be charged from a usual l15-vo1t AC source through the use of a crystal recifier 47 with a resistor 48 to limit the current to a safe charging value. The contacts 49 of the relay RL2 disconnect the battery from the rest of the instrument before they come in contact with a charging current so that the remainder of the instrument is insulated. The portions of the device described above other than the hand piece illustrated in FIGURES 1 and 2 may be carried within a box which may be carried by a strap over the shoulder of the user.

While the preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.

What is claimed is:

1. A device for testing the tensile strength of fabric and the like when in open width including, a pair of aligned supports, mounting means carrying said supports for guided movement in a direction away from each other, a plurality of spaced aligned sharp prong-like elements carried by each of said supports on a bottom surface thereof, said prong-like elements carried by respective supports extending outwardly thereof away from said supports such that portions of said prong-like elements overlie respective supports, said prong-like elements passing into and accommodating the fabric between portions of said prong-like elements overlying said supports and the supports effecting a grip on the fabric resisting tension in the fabric between prong-like elements carried by respective supports produced by movement of the supports in a direction away from each other, and power operated means connected to said supports for applying a predetermined testing force moving said supports away from each other against the tension of the fabric, said device being portable and adapted to be placed manually on the fabric, whereby said device may be placed in any desired location on an open width of fabric and a force applied thereto between the supports for testing the tensile strength of the fabric.

2. The structure set forth in claim 1, wherein the device includes a handle connected to said aligned supports on a portion thereof opposite said prong-like elements, and wherein said power operated means includes means automatically limiting the force applied to said supports tending to move said supports away from each other.

3. A device for testing the tensile strength of fabric and the like when in open width including, a pair of aligned supports each having a flat horizontal lower surface, mounting means carrying said supports for guided movement toward and away from each other, a plurality of space aligned sharp prong-like elements carried upon the lower surface of each of said supports, said pronglike elements carried upon respective lower surfaces extending outwardly thereof away from said lower surfaces at an angle with respect to respective lower surfaces such that portions of said prong-like elements overlie respective lower surfaces, said angle being sufficient for the prong-like elements to pass into and accommodate the fabric between portions of said prong-like elements overlyin-g said lower surfaces and the lower surfaces effecting a grip on the fabric resisting tension in the fabric between prong-like elements carried by respective lower surfaces produced by movement of the supports away from each other, and fluid pressure operated means connected to said supports for applying measured controlled increasing testing force moving said supports toward and away from each other against the tension of the fabric, said device being portable and adapted to be placed manually on the fabric, whereby said device may be placed in any desired location on an open width of fabric and a force applied thereto between the supports for testing the tensile strength of the fabric.

4. A portable device for testing the tensile strength of dryer-felts and the like when in open Width including, a pair of aligned housings, a pair of aligned supports carried by said housings respectively, each support having a fiat horizontal lower surface, a pair of parallel spaced mounting bars carried upon said housings slidably guiding said supports for movement toward and away from each other, a plurality of spaced aligned sharp prong-like elements carried upon the lower surface of each of said supports, said prong-like elements carried upon respective lower surfaces extending outwardly thereof away from said lower surfaces at an angle with respect to respective lower surfaces such that portions of said pronglike elements overlie respective lower surfaces, said angle being sufficient for the prong-like elements to pass through and accommodate the fabric between portions of said prong-like elements overlying said lower surfaces and the lower surfaces effecting a grip on the fabric resisting tension in the fabric between prong-like elements carried by respective lower surfaces produced by movement of the supports away from each other, fluid pressure operated means connected to said supports for applying measured controlled increasing testing force moving said supports away from each other against the tension of the fabric including, a cylinder carried by one of the housings, a piston in said cylinder, a piston rod carried by said piston on one end thereof and having connection on the other end on the other housing between said bars, said cylinder and piston rod being parallel to said bars, and means indicating the fluid pressure during the moving of said supports away from each other, said device being portable and adapted to be placed manually on the fabric, whereby said device may be placed in any desired location on an open width of fabric and a force applied thereto between the supports for testing the tensile strength of the fabric.

References Cited UNITED STATES PATENTS 682,785 7/1901 Caldwell.

924,579 6/1909 Perkins 73-97 1,779,294 10/ 1930 Schlaich ZOO-81.8 3,031,618 4/1962 Palermo et al 73-102 X 3,039,299 6/1962 Roof 7396 FOREIGN PATENTS 834,769 3/ 1952 Germany.

JAMES J. GILL, Acting Primary Examiner. RICHARD C. QUEISSER, Examiner. I. H. WILLIAMSON, Assistant Examiner. 

1. A DEVICE FOR TESTING THE TENSILE STRENGTH OF FABRIC AND THE LIKE WHEN IN OPEN WIDTH INCLUDING, A PAIR OF ALIGNED SUPPORTS, MOUNTING MEANS CARRYING SAID SUPPORTS FOR GUIDED MOVEMENT IN A DIRECTION AWAY FR OM EACH OTHER, A PLURALITY OF SPACED ALIGNED SHARP PRONG-LIKE ELEMENTS CARRIED BY EACH OF SAID SUPPORTS ON A BOTTOM SURFACE THEREOF, SAID PRONG-LIKE ELEMENTS CARRIED BY RESPECTIVE SUPPORTS EXTENDING OUTWARDLY THEREOF AWAY FROM SAID SUPPORTS SUCH THAT PORTIONS OF SAID PRONG-LIKE ELEMENTS OVERLIE RESPECTIVE SUPPORTS, SAID PRONG-LIKE ELEMENTS PASSING INTO AND ACCOMMODATING THE FABRIC RESISTING TENSION SAID PRONG-LIKE ELEMENTS OVERLYING SAID SUPPORTS AND THE SUPPORTS EFFECTING A GRIP ON THE FABRIC RESISTING TENSION IN THE FABRIC BETWEEN PRONG-LIKE ELEMENTS CARRIED BY RESPECTIVE SUPPORTS PRODUCED BY MOVEMENT OF THE SUPPORTS IN A DIRECTION AWAY FROM EACH OTHER, AND POWER OPERATED MEANS CONNECTED TO SAID SUPPORTS FOR APPLYING A PREDETERMINED TESTING FORCE MOVING SAID SUPPORTS AWAY FROM EACH OTHER AGAINST THE TENSION OF THE FABRIC, SAID DEVICE BEING PORTABLE AND ADAPTED TO BE PLACED MANUALLY ON THE FABRIC, WHEREBY SAID DEVICE MAY BE PLACED IN ANY DESIRED LOCATION ON AN OPEN WIDTH OF FABRIC AND A FORCE APPLIED THERETO BETWEEN THE SUPPORTS FOR TESTING THE TENSILE STRENGTH OF THE FABRIC. 